Anti-deformation device for longitudinal seam welding of C-shaped structure coil box

The invention relates to an anti-deformation device for longitudinal seam welding of a C-shaped structure coil box, the coil box comprises a bottom plate and two side plates which are both of an arc-shaped structure, the side plates are welded to the two sides of the bottom plate, a concave cavity is formed in the lower portion of the coil box after the coil box is welded, the anti-deformation device comprises a supporting frame of a concave structure, and the supporting frame is provided with a clamping groove; a groove is formed in the top; the horse riding elements are in a long strip shape, are fixedly arranged on the bottom surface of the groove of the supporting frame at intervals and are used for fixedly supporting the side plates; and the plurality of inner cavity shaping plates are fixedly arranged on the corresponding horse riding elements respectively and are used for supporting the bottom plate. The invention further provides a welding method which is realized by adopting the anti-deformation devi